JP2003293981A - Turbo molecular pump system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the reliability of a turbo molecular pump by incorporating various types of sensor amplifiers in a pump body. <P>SOLUTION: A temperature sensor 14 for temperature detection heated by a heater 13 and a temperature sensor amplifier 35 for amplifying detection signals from the temperature sensor 14 are incorporated in the pump body having electromagnets 5, 6, and 7 forming a magnetic bearing, position detection sensors 8, 9, and 10, and a motor 4. Thus, the effect of external noise in the measurement of temperature of the pump is reduced. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbo molecular pump system, which is particularly used in semiconductor manufacturing equipment,
The present invention relates to a turbo molecular pump system in which a rotating shaft is supported by a magnetic bearing and rotates at high speed.

[0002]

2. Description of the Related Art FIG. 8 is a longitudinal sectional view of a conventional turbo molecular pump body, and FIG. 9 is a system conceptual view of a turbo molecular pump device.

In FIG. 8, a turbo molecular pump 1 includes a rotary shaft 3 and a stator 2. The lower end side of the rotary shaft 3 and the upper and lower sides of the rotary shaft 3 are opposed to each other, and the rotary shaft 3 and the stator 2 are relatively opposed to each other. Position detection sensors 8, 9 and 10 for detecting the position are provided. The detection signals of the position detection sensors 8, 9, 10 are
The position detection sensor amplifier 31 in the pump controller 21 shown in FIG. 9 outputs the position detection signal (analog signal or digital signal) of the rotary shaft 3 from the position detection sensor amplifier 31. Electromagnets 5, 6 and 7 for supporting the rotating shaft 3 by magnetic bearings are provided on the upper side and the lower side of the rotating shaft 3. Further, a motor 4 for rotationally driving the rotary shaft 3 is provided so as to face the central portion of the rotary shaft 3.

The motor 4 is rotationally controlled by a motor controller 29 shown in FIG. 9, and the magnetic bearings by the electromagnets 5, 6, 7 are controlled by a magnetic bearing controller 28. The magnetic bearing controller 28 and the motor controller 29 are arranged in a pump controller 21 provided outside the pump body. Further, emergency bearings 11 and 12 are provided at the upper and lower ends of the rotary shaft 3. The emergency bearings 11 and 12 support the rotary shaft 3 when the magnetic bearing device becomes out of control.

Although not shown in FIG. 8, the rotation detecting sensor 25 for detecting the number of rotations of the rotating shaft 3 is provided in the stator 2.
The rotation detection sensor amplifier 30 in the pump controller 21 has its signal as shown in FIG.
A rotational speed signal of the rotary shaft 3 is generated via the.

The position detecting sensors 8, 9 and 10 are generally magnetic sensors represented by a reluctance type or an eddy current type, and the rotation detecting sensor 25 is a Hall IC or a magnetic sensor. When this turbo molecular pump is used in a process that generates a large amount of reaction products such as etching and CVD (Chemical Vapor Deposition),
This reaction product adheres to the inside of the pump body,
The rotation of may become defective.

Therefore, in order to prevent the accumulation of reaction products, it is common to control the pump temperature to a high temperature by heating with a heater 13 arranged in the pump body 20.
Therefore, the temperature sensor 14 is provided in the pump body 20, and the output of the temperature sensor 14 is amplified by the temperature sensor amplifier 35 arranged in the pump controller 21. After the calculation by the heater controller 32 of the heater 13, the power is supplied to the heater 13 through the switch 33 that turns on and off the power to the heater 13.
Be thrown into.

Further, in the pump controller 21,
A communication unit 34 that enables communication with the outside is provided so that the operating status of the magnetic bearing can be output to the outside or operated by a command from the outside.

[0009]

In the conventional turbo molecular pump device, a thermocouple, a platinum resistance element, or a thermistor is used as the temperature sensor 14 arranged in the pump body 20. When a thermocouple is used for the temperature sensor 14, it is necessary to use a special electric wire such as a compensating lead wire up to the thermocouple amplifier, but generally the cable length is as long as several meters to several tens of meters.
Noise is superimposed during this period, and there is a high possibility that reliability will become a problem in temperature measurement. Also, when a platinum resistance element or a thermistor is used, the signal line becomes long, and the same problem may occur.

Further, the power to the heater 13 is supplied to the switch 3
Since the power is supplied by switching on / off of 3, the magnetic bearing control may be affected when the power supply cable from the pump controller 21 to the heater 13 is brought close to another magnetic bearing control cable.

The rotation detecting sensor 25 and the position detecting sensors 8, 9 and 10 placed in the pump body 20 are also connected via the cable 22 to the rotation detecting sensor amplifier 30 and the position detecting sensor amplifier 31 inside the pump controller 21, respectively. Since the position detection signal and the rotation signal are generated by these amplifiers, the transmission length of the signal becomes long as in the case of the above-mentioned heater control, and it is easily affected by external noise. There was such a problem.

Therefore, the main object of the present invention is to solve the above-mentioned problems of the conventional turbo molecular pump device with a heater controller, and to stably prevent the deposition of reactive products in the pump by high temperature control. You can
Furthermore, it is an object of the present invention to construct a stable turbo molecular pump system by making the rotational speed and position detection of the rotating shaft less susceptible to external noise.

[0013]

According to the present invention, a pump main body whose rotating shaft rotates with magnetic bearings and a pump controller for controlling the pump main body are connected by a cable,
A turbo molecular pump device in which the temperature of the pump body is adjusted by a heater is characterized by including a temperature sensor arranged inside the pump body and an amplifier for amplifying the output of the temperature sensor.

By arranging the temperature sensor amplifier in the pump body in this way, the weak signal transmission path from the temperature sensor to the amplifier can be shortened, thereby improving the reliability of temperature measurement. You can

Further, it is characterized in that it is provided with a switch built in the pump body for controlling electric power to the heater and a heater controller for controlling the switch.

By thus incorporating the switch for supplying electric power to the heater in the pump main body, the switch from the switch whose voltage level is digitally changed to the heater is changed from within the cable connecting the pump main body and the pump controller. The cable can be omitted, and the influence of noise on other cables can be eliminated.

Further, the heater controller is built in the pump main body, and controls the heating by the heater according to a command from the outside of the pump main body.

As described above, by incorporating the heater controller in the pump, the heater control is entirely contained in the pump main body, and the cable (harness) required for the heater control is eliminated. As a result, the system reliability is improved and the cost is reduced. Can be achieved.

Further, the output from the amplifier for the temperature sensor is a digital signal.

By using the digital signal, the measurement result can be accurately transmitted to the controller even if the cable length is long.

Further, the present invention is characterized in that a cable connecting between the pump body and the pump controller and a cable used for supplying electric power to the motor and the heater are provided separately from other cables.

With this structure, it is possible to suppress the influence of noise generated from the power supply cables of the motor and the heater, which mainly supply power, from affecting the others, and to improve the reliability of the entire pump system. You can

According to another aspect of the present invention, a pump main body whose rotary shaft rotates with magnetic bearings and a pump controller for controlling the pump main body are connected by a cable, and a rotation detecting sensor for measuring the rotational speed of the rotary shaft in the pump main body. The turbo molecular pump device having the above is characterized by including a rotation sensor amplifier which is built in the pump body and amplifies the output of the rotation sensor.

By arranging the rotation sensor amplifier inside the main body as described above, the weak signal transmission path from the rotation sensor to the amplifier can be shortened, thereby improving the reliability of rotation measurement. it can.

Further, the present invention is characterized by including a position detecting sensor arranged in the pump body for detecting the position of the rotary shaft and a position detecting sensor amplifier for amplifying the output of the position detecting sensor.

By arranging the amplifier for the position detecting sensor of the rotary shaft in the pump body in this way, the weak signal transmission path from the position detecting sensor to the amplifier can be shortened, and thereby the position of the rotary shaft can be reduced. The reliability of measurement can be improved.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below.
A detailed description will be given with reference to the drawings.

FIG. 1 is a block diagram showing the overall configuration of a turbo molecular pump according to the first embodiment of the present invention. 1, in this embodiment, as compared with the conventional example shown in FIG.
The feature is that it is placed inside.

Signal transmission from the temperature sensor amplifier 35 to the pump controller 21 may be either an analog signal or a digital signal. When a digital signal is used, there is an advantage that even when transmitting data from a plurality of temperature sensors 14, several signal transmission cables can be used.

In this embodiment, the temperature sensor amplifier 35
By incorporating the above, it is possible to shorten the distance between the temperature sensor 14 and the temperature sensor amplifier 35, and reduce the influence of electrical noise superposed between them.

Further, in FIG. 1, the pump main body 20 and the pump controller 21 are connected only by the cable 22, but a plurality of cables may be used. In particular, by grouping only cables having a high possibility of noise generation and having a high voltage level as separate cables and separating them from the other cables and connecting the pump controller 21 to the pump main body 20, noise to other cables can be reduced. The impact can be reduced. That is, in FIG. 1, only the cable connecting the motor controller 29 and the motor 4 and the cable connecting the switch 33 and the heater 13 are arranged separately from the other cables, thereby reducing the influence of noise. can do.

FIG. 2 is a block diagram showing the overall structure of a turbo molecular pump according to the second embodiment of the present invention. In this embodiment, not only the temperature sensor amplifier 35 is built in the pump body 20 as in the embodiment of FIG. 1, but also a switch 33 connected between the heater 13 and the heater controller 32 is built in the pump body 20. The feature is that it does. In this embodiment, the switch 33 is also incorporated in the pump main body, so that the latter stage of the switch 33 (the cable between the switch 33 and the heater 13) and another cable are not adjacent to each other. This switch 33
Has the role of switching the supplied AC or DC voltage. Therefore, a rectangular wave voltage is applied to the cable between the switch 33 and the heater 13 in the subsequent stage, and electromagnetic noise is generated.

On the other hand, by incorporating the switch 33 in the pump body 20 as in this embodiment, the distance between the switch 33 and the heater 13 can be shortened and the influence of noise to the outside can be reduced. can do.

FIG. 3 is a block diagram showing the overall configuration of a turbo molecular pump according to the third embodiment of the present invention. This embodiment is characterized in that not only the temperature sensor amplifier 35 and the switch 33 are built in the pump body 20 as in the embodiment of FIG. 2, but also the heater controller 32 is built in the pump body 20. In this embodiment, since all the temperature control components of the heater 13 are placed inside the pump body 20, it is possible to arrange these components close to each other or to arrange them at the same place. Therefore, as a result of eliminating the cable (harness) required for heater control, the reliability of the system can be improved and the cost can be reduced.

Further, in FIG. 2, the pump main body 20 and the pump controller 21 are described to be connected only by the cable 22, but a plurality of cables may be used. In particular, by collecting only cables having a high possibility of noise generation and having a high voltage level as separate cables and separating them from the other cables and connecting the pump controller 21 to the pump main body 20, the noise to other cables is prevented. The impact can be reduced. That is, in FIG.
By arranging only the cable connecting the motor controller 29 and the motor 4 and the cable connecting the heater controller 32 and the switch 33 away from the other cables, the influence of noise can be reduced.

FIG. 4 is a block diagram showing the overall structure of a turbo molecular pump according to the fourth embodiment of the present invention. This embodiment is similar to the embodiment of FIG. 3 in that the temperature sensor amplifier 35, the switch 33, the heater controller 3
The feature is that not only the pump 2 is built into the pump body 20, but also the rotation detection sensor amplifier 30 is built into the pump body 20. In this embodiment, the rotation detection sensor amplifier 30 is housed inside the pump body 20 and placed near the rotation detection sensor 25, so that the output of the rotation detection sensor 25 can be input to the rotation detection sensor amplifier 30 without being attenuated. it can. As a result, it is possible to reliably detect the number of revolutions even when the rotating shaft 3 rotates at a high speed.

FIG. 5 is a diagram showing an overall configuration relating to rotation detection in which a Hall IC is used as the rotation detection sensor 25. In FIG. 5, the Hall IC 41 is opposed to the permanent magnet 40 attached at one position on the end of the rotary shaft 3, and the Hall IC 41
Is output to the comparator 43, which is a part of the rotation detection sensor amplifier 30, via the cable 50. The comparator 43 compares the signal 49 from the Hall IC with a preset threshold voltage 47 and outputs the output as a rotation pulse 51.

Here, a resistance 45 and a capacitance 46 exist inside the cable 50. Since these values are proportional to the cable length, when the long cable is used, the resistance 45 and the capacitance 46 are used. 46 will increase.

In FIG. 6, when the rotation detecting sensor 25 and the rotation detecting sensor amplifier 30 are separated from each other and a long cable is connected between them, and when the rotation detecting sensor 25 and the rotation detecting sensor amplifier 30 are brought close to each other. It is a figure which shows the signal transmission characteristic at the time of connecting with a short cable. In particular, FIGS. 6A and 6B show the characteristics over time of the signal 49 and the rotation pulse 50 when the rotary shaft 3 rotates at a low speed, and FIG.
(D) shows the time characteristics of the signal 49 and the rotation pulse 51 when rotating at high speed. Further, in each characteristic, the solid line shows the case where the cable is long, the dotted line shows the signal when the cable is short, and the alternate long and short dash line shows the level of the threshold value 47.

From FIG. 6, when the cable is long, the rising and falling edges of the signal 49 are gentle, and this is because the resistance 45 and the capacitance 46 existing in the cable are affected. Further, when the rotating shaft 3 rotates at a high speed, this effect becomes remarkable and the signal 49 is always lower than the set threshold value 47, so that the rotating pulse 51 cannot be obtained. .
By thus shortening the cable, in other words, by bringing the rotation detection sensor 25 and the rotation detection sensor amplifier 30 close to each other, it is possible to obtain a stable rotation pulse even at high speed rotation.

FIG. 7 is a block diagram showing the overall configuration of a turbo molecular pump according to the fifth embodiment of the present invention. In this embodiment, not only the temperature sensor amplifier 35, the switch 33, the heater controller 32, and the rotation detection sensor amplifier 30 are built in the pump body 20 as in the fourth embodiment shown in FIG. Three
The feature is that 1 is also incorporated in the pump body 20.

In this embodiment, the position detection sensor amplifier 3
By incorporating 1 therein, the distance between the position detection sensors 8, 9 and 10 and the position detection sensor amplifier 31 can be shortened, and the influence of electrical noise superposed between them can be reduced.

The embodiments disclosed this time are to be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

[0044]

As described above, according to the present invention, by arranging various sensor amplifiers in the pump body, it is possible to shorten the weak signal transmission path from various sensors to the amplifiers. The reliability and cost reduction can be achieved.

[Brief description of drawings]

FIG. 1 is a diagram showing an overall configuration of a turbo molecular pump according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an overall configuration of a turbo molecular pump according to a second embodiment of the present invention.

FIG. 3 is a diagram showing an overall configuration of a turbo molecular pump according to a third embodiment of the present invention.

FIG. 4 is a diagram showing an overall configuration of a turbo molecular pump according to a fourth embodiment of the present invention.

FIG. 5 is a diagram showing an overall configuration relating to rotation detection in which a Hall IC is used as a rotation detection sensor.

FIG. 6 is a waveform diagram showing signals related to rotation detection.

FIG. 7 is a diagram showing an overall configuration of a turbo molecular pump according to a fifth embodiment of the present invention.

FIG. 8 is an explanatory diagram related to a pump body of a conventional turbo molecular pump.

FIG. 9 is an explanatory diagram related to the overall configuration of a conventional turbo molecular pump.

[Explanation of symbols]

3 rotary shafts, 4 motors, 5, 6, 7 electromagnets, 8,
9, 10 Position detection sensor, 13 Heater, 14 Temperature sensor, 20 Pump body, 21 Pump controller, 25 Rotation detection sensor, 28 Magnetic bearing controller, 29 Motor controller, 30 Rotation detection sensor amplifier, 31 Position detection sensor amplifier, 32 heater Controller, 33 switch, 34 communication unit, 35
Temperature sensor amplifier, 40 permanent magnets, 41 Hall I
C, 43 comparator, 50 cable.

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification Code FI Theme Coat (Reference) F04D 29/58 F04D 29/58 LF Term (Reference) 3H021 AA02 AA08 BA01 BA11 BA18 BA20 BA30 CA06 CA07 DA00 EA05 EA07 3H022 AA01 BA07 CA48 CA50 DA01 DA09 DA12 3H031 DA02 EA09 EA11 EA12 EA13 EA14 EA15 FA41

Claims (7)

[Claims] 1. A turbo-molecular pump device in which a pump main body having a rotary shaft rotating by magnetic bearings and a pump main body for controlling the pump main body are connected by a cable, and the temperature of the pump main body is adjusted by a heater. A turbo molecular pump system comprising a temperature sensor arranged inside the main body and an amplifier for amplifying an output of the temperature sensor. 2. The turbo molecule according to claim 1, further comprising a switch built in the pump main body, the switch controlling electric power to the heater, and a heater controller controlling the switch. Pump system. 3. The turbo-molecular pump system according to claim 2, wherein the heater controller is built in the pump body and controls heating by the heater according to a command from the outside of the pump body. 4. The turbo-molecular pump system according to claim 1, wherein the output from the amplifier for the temperature sensor is a digital signal. 5. A cable connecting between the pump main body and the pump controller and a cable used for supplying electric power to the motor and the heater are provided separately from other cables. The turbo molecular pump system according to any one of claims 1 to 4. 6. A rotation detecting sensor for measuring the number of rotations of the rotary shaft in the pump main body, wherein a pump main body whose rotary shaft rotates with magnetic bearings and a pump controller for controlling the pump main body are connected by a cable. A turbo molecular pump system having a rotation sensor amplifier built in the pump body for amplifying an output of the rotation sensor. 7. Further disposed within the pump body,
The turbo molecular pump system according to any one of claims 1 to 6, further comprising a position detection sensor that detects a position of the rotation shaft and a position detection sensor amplifier that amplifies an output of the position detection sensor.